Abstract: An MPEG video decoder adapted to decode an incoming MPEG coded video data stream to form decoded MPEG video data and to reconstruct from the decoded MPEG video data a raw video signal, utilizes: an n×n block of decoded video data discrete cosine transform values forming an original matrix having a non-zero value in a preselected corner location in the matrix; and a modified matrix forming apparatus adapted to form a modified matrix having the same content as the original matrix with the exception of a zero in the preselected corner value position; a dummy matrix forming apparatus adapted to form a dummy matrix having zero in each of its matrix positions with the exception of the preselected corner position; an inverse discrete cosine transform apparatus adapted to perform an inverse discrete cosine transform algorithm on the modified matrix and the dummy matrix; and an adder which adds the inverse discrete cosine transform of the modified matrix and the dummy matrix to produce the inverse discrete cosin